Packing head for oil wells



Feb. v28, 1939. A. `I .vs'roNE ET AL 2,143,844

v v v PACKING HEAD FOR OIL WELLS l Filed Oct. 2, 1936 ."5 Sheets-'Sheetl v Feb. v.23, 1939.

A. sTvNE ET AL PACKING HEAD FOR OIL WELLS Filed oct. 2, 193e 3Sheets-Sheet 2 Inventar; lrl l Stolze, FIWIIZ'JZ Sawyer.

A. l.. 'sToNE ET AL v PACKING HEAD FOR OIL WELLS Fehlzs, 1939. .y

s sheets-sheet Filed Oct. 2, 1936 /00 Iride/liar? .lbe'll 512226,

Patented Feb. 28, 1939 UNITED STAT ES;

PATENT OFFICE PACKING FR. OIL VVLLSl tion of California ApplicationOctoberl 2,

8 Claims.

This invention has to do generally with` devices ffor sealing aroundwork, e. g. drill pipe and the like, in` oil well drilling operations.In. certain of its aspects, the invention is directed to 5, improvementsin packing heads of the type disclosed: in the. copending applicationsof Frederick Stone et al., on. Packing head, Serial Number 50,482, ledNovember 19, 1935, now Patent No. 2,124,015, issued Julyv 19,v 1938, andOil Well packlo: ing, heads, Serialf Number 97,632, filed August 24,

@ne ofl our principal objects is to alter and. simplify the type ofpacking head constituting the subject-matter ofy the copendingapplications rev,1 ferredf to,'for the purpose of better adapting thehead to simpler and:` more economical manufacture, and to certain useswhere all` the features of the earlier `disclosed inventions may not/beriequired. In accordance with the present invention', we, have providedan improved form of packing heady capable of general use for sealingaround work of various types, shapesv and sizes, and possessing,notwithstanding its simplicity, the capability of controllable positiveaction that insures dependableY operation and prolonged service.

The invention also embodies another feature of outstanding: importance,that distinguishes it from all prior packing heads or similar devices ofwhich wev are aware. We refer here to the utility of the invention asastripper that may be used, for example, to. maintain by means of asingle packer,v a fluid tighty seal about. elongated work having crosssectional enlargements, for example, collared pipe, as the Work isbei-ng pulled from "z or lowered into the well. Although the packingheads disclosed in tliev above mentioned copending applications also.have been` found to be capable of such operation as strippers, as Wellas for sealing: about work that remains without great variation in itscross sectional size or area, the present forms. rif-packing heads arein general better adapted` to thaty type of operation. Different formsof strippers have been proposed, and vsomey are in common use,A but ourimproved de;- vice diiers from all these in that it involves adistinctly different. structure and mode of operation, particularly as'regards the provision for rendering the packer expansible to pass thepipe collar, and yet capable of maintaining at all times an effectiveseal about the. pipe.

Referring particularly to its stripper aspect, thel invention may bedescribed briefly as comprising an expansivepacker together with amovable packing contracter, preferablyv though not 55 necessarilyin thebroaderaspects ofthe inven- 1936, Serial No. 103,678y

tion, a fluid pressure actuated piston, that yieldably bears against thepacker to maintain it in radially constricted condition about the work.The coaction between the packer and. the contractor isl reciprocal inthat the packer' is radially constricted by movement of the contractor,andthe latter-isr inturn displaceable ln response to expansion ormovement of the 'packer'. Advantagev isV taken of this condition toadapt the device for use as a stripper, the contractor serves tomaintain the packer constricted about the smaller diameter pipe, butenables the packer. to pass the pipe collar because when the packer isexpanded by movement of a pipe collar into it, the contractor is'accordingly displaced by the packer expansion, permitting the collar topass through the packer. Thereafter, the contractor immediately closes.the packer about the smaller diameter pipe.

All the various features and objects will be more fully explained andunderstood to better advantage inthe following detailed description ofthe invention in certain of its typical and illustrative forms.Throughout the description reference is had to the accompanyingdrawings, in which:

Fig. 1` is a sectional view showing a typical form of invention, withthe packer in expanded positiij' Fig. 2 is a View similar to Fig. 1showing the packer constricted' about the work;

Fig. 3 is a sectional View' illustrating a variational form` of theinvention;

Fig'.y 4 is a similar' view showing a modication of the form of Fig, 3;and

Figs. 5 and 6 show additional variant forms in which the packercontractor moves downward against the direction of well flow.

Referring ilrst to Fig. 1, the packing head generally indicated at I0and mounted on the Well casing IIi, comprises a body I2 that mayconveniently be made in two sections, the upper section Iii beingthreaded at I4 on the lower section I5, and the latter attached at I6 tothe casing by a threadedconnection or in any other suitable manner.lSuitable packing I'I may be interposed between the body sections toprevent fluid leakage through the joint at I4. Upper body section I3 isshaped to provide an annular cylindric walled chamber I8 to receive thelater described packer contracting piston, and has an inner tubular wallI 9 with downwardly tapering surfaces 20 and 2| at the upper and lowerends of the counterbore 22. The opening or bore 23 through the bottominwardly flanged end 24 of the tubular wall I9 is of suicient diameterto pass the maximum diameters of the work 25, for example, pipecouplings 26, the drill bit (not shown), or other tools that may becarried in the pipe string. The lower body section I5 has a cylindricbore 21 within which the contractor piston works, and an lannularshoulder 28 at the bottom of the bore that serves as a stop to limit thedownward travel of the piston.

The tubular packer contracting piston 29 com prises an upper enlargeddiameter portion 29a having a substantially sliding fit with the bodybore 30 and the outer cylindric surface lila, of wall I3, and a lowerreduced diameter portion 29h slidably tting the wall of counter-bore 21in the lower body section I5. The piston carries packing rings 32 toprevent fluid leakage along the piston from either chamber I8 or space33, the lower section also containing packing rings 34 that preventfluid leakage along the piston from yeither space 33 or chamber 35within the head below the packer. The piston may be regarded as havingthree pressure areas: the up'- wardly facing surface 3B on the top ofthe p-iston exposed to 'chamber I8, the downwardly facing surface 31formed on the piston intermediate its ends and exposed to space 33, anda pressure area generally indicated at 38, on the lower end of thepiston, the last mentioned area corresponding to thearea lbetween thework 25 and the lower body section counter-bore 21. For reasons thatwill later appear, it'isdesirable, as isthe case, that pressure area 36be greater thanv pressure area 38, in Vorder that the piston may becaused to move downward'by the application of the same fluidpressure perunit-arcate the two surfaces.

A suitable flexible packer 4I, preferably in the form of a continuouslyannular (as distinguished from segmental annular) rubber sleeve, isconflned between the inwardly projecting piston flange 40 and the lowerend of the inner tubular portion I9 of the upper body section.Asillustrated, the packer has a straight rbore 42 with annular clearancein its expanded condition about the work 25, the outer diameter andshape of the packer being made to snugly fit the piston'bore 43 and theVtop surface of ange 40. While either or both ends of the packer may beconnected to the adjacent shouldered surfaces against which the packerends bear, the packer is shown typically as being fastened to the bottomofthe body flange 24. Our preferred form of packer connection comprisesa fabric 44 embedded in the rubber' at the upper 'and'outer' interiorofthe packer and clamped between `flange 24 and a ring 45 held tightly tothe'ilange by screws 46. The bottom surface of the ring maybe providedwith annular concentricridges 41 which'form grooves or recesses in'towhich the rubber is forced upon longitudinal compression, and fromfwhichthe air is thereby expelled, so that lthe'pressure applied to the packeralso serves as a means of securely holding it to its support. The fabric44 provides an effective and durable connection for anchoring the packerto the support, in that it is adapted to withstand 'the strains anddistortions to which the packer is subjected in being constricted aboutthe work, 'and in being forced tosome extent up through-the flange Ybore23, when the packer is holding extremely high well 'pressuresl Asillustrated in Fig. '2, upon upward movement of the `piston 29, packer4Iy is constricted radially into'sealing engagement with the work due tolongitudinal compression between stationary supporting nange 24 and theYinterior piston flange 40. Where the apparatus is to be used for generalpurposes as a packing head or stripper it is desirab-le to limit theupward piston travel and therefore the extent of packer constrictionabout the work. For example, -to reduce wear on the packer when employedto seal about a drill pipe or a polygonal cross sectional kelly duringdrilling operations, it is desired 'to limit the packer contraction tovthe point where a slight leakage of well fluid will be allowed throughthe packer to lubricate its engagement with the work. It is alsodesirable that piston limiting or stop means be adjustable and capableof regulation to compensate for wear on the packertending to enlarge itsnormal bore diameter.

In accordance with the invention we have provided an improved type ofpiston stop means in the form of adjustable screws 53 threaded at 5Iinto the piston and extending through .the top wall of the body,suitable packing 5I held in place by retaining ring 52 being providedtol prevent fluid leakagel past Athe screws. Each of the stop screws hasa flange 53 that cornes into engagement with ring 52 to limit the upwardtravel of the piston as shown in Fig. 2, all the screws of course being.correspondingly adjusted to give flanges 53 the same spacing from thepiston.

The contactor piston is operated by f fluid pressure, preferably gas ormixed gas and liquid, communicated selectively to chamber-I8 and space33 by way of pipes 54 and 55. The piston operating uid may be derivedfrom any suitable source, for example from. the well casing via line 56,or from an independent source through line 51. The communication of thepressure fluid to lines 54 vand 55 is controllable by affour-way valvediagrammatically shown at 51. With the valve positionedY as VshowninFig. 1, the operating uid pressure is communicated to chamber I8 and tothe upper pressure area 3S of the-piston to maintain the latter in itslower position and the packer 4I in radially expanded condition. Thepressure'in space 33 is released via pipe 55 communicating witlr theexhaust line 58. To constrict the vpacker about the` work, `the positionof valve 51 is reversed, venting chamber I8 to the exhaust line, andcommunicating the pressure fluid to space Y33, the application of thefluid pressure to piston surface 31 causing the piston to move upwardand to constrict the packer, as shown in Fig. 2. To again open thepacker, valve 51 is returned to the position illustrated, and althoughthe pressures then applied to piston areas 36 and 38 may be the samewhen the well pressure is employed to, operate the piston, the latterwill move downward by reason of the differential in the areas asdescribed above.

In normal drilling operations the packer may be maintained constrictedabout the Work, the drill pipe or polygonal cross sectional kelly, wherethe Well is under pressure. The head also may be used as a blow-outpreventer to close about the work in the event of sudden development ofhigh well pressures. Assuming the packer to be open, as in Fig. 1, andthe well to suddenly develop high pressure, the packer may beimmediately closed by communicating the pressure viiuid to space 33 toraise the contractor piston.

We have previously referred to the particular advantage of the inventionin being capable of operation as a stripper capable of passing andmaintaining a fluid tight seal about. successive lengths or stands Yofcollared pipe being pulled from or lowered into the well. Theadaptability of the head for use as a stripper results from thedisplaceability of the piston as a result of packerV expansion by thepipe collars, tov permit the collars to pass through'the. packer.Assuming that the pipe string is being pulled from the well with thepacker closed about the pipe and a collar 26 raised tothe point Where ithas enteredy the lower endof the packer as shown in Fig. 2, continuedupward' movement of the collar tends to displace and to longitudinallyexpand the packer. The result is that the rubber tends to flow andthelifting force on the collar to be transmitted through the rubber to thepiston ange 40, causing the piston to be displaced downwardly a distancesufcient' to accommodate the volume of vrubber displaced' by the collaras it enters and moves through thev packer bore. Consequently, by reasonoi' the displaceabi'lity of the piston by the packer, it has been foundpossible to pull the collar through the packer at any desired speed andWithout excessive wear on the rubber or damage to the packer.`Displacement oi the piston is yieldably resisted by the fluid containedin space 33, the connecting lines and the chamber rbelow the piston(valve v51 being reversed from the positions of Fig. l) and as a result,the packer at all times. during this operation tightly engages thesurfacev of the collar and immediately constricts about the smallerdiameter pipe as the collar moves out: of the packer. As will beapparent, the same piston-action in response to expansion of the packeroccurs as the pipe string is being lowered into the well.

While generallysimilar to the described form of the invention shown inFigs. 1 to 2, the variational Yform of Fig., 3 differs mainly withrespect to thebody structure and its attachment to the casing, thepacker mounting (the packer in this form being carried vby the piston),and the provision of a tapered body shoulder or bore cooperatingwiththe; piston to radially constrict the packer. rIn Fig. 3 the body 60has a counter-bore 6| and a lower reduced diameter bore 62 containingthe piston 63, the downward travel of the piston being limited byengagement with stop shoulderA 64,. with clearance providedI at 65 toreceive the operating fluid introduced through line 55. Here the packer66 is seated within the comparatively large diameter piston counter-bore61, the. lower portion 63a and body bore 62 being of reduced diameter sothat the piston pressure area 31 is somewhat larger than thecorresponding area 31 in Fig. l, and the bottom pressure area 38 iscomparatively smaller. Likewise, the differential between the top pistonarea 36' and the bottom pressure area 38', is comparatively greater thanin the first described form.

The body is attached toA the casing by a type ofV joint 68 that may bebroken without requiring rotation or substantial elevationr of the head,and permitting the head1 to be shifted laterally to one sidewhen thejoint is disconnected. The lower end of the body has a tapered shoulderG9 that seats on the top correspondingly shaped surface of a sleeve Tthreaded at 'H on the casing.

Sleeve 12, threaded at 13 on the body and having bodily movable with thepiston in its vertical travel. The connection between the packer and thepiston is similar to the previously described form, and comprises afabric 11 embedded in the outer interior of the packer and clampedbetween the annularly grooved ring 18 and the upwardly facing pistonsurface 1'9. As the piston is moved upwardly, the packer is radiallyconstricted by movement along the tapered bore 80 of head 8l threaded at82 into` the upper end of the body. In assembling the apparatus, thepiston rst may be raised to insert the stop screws through openings 83kin head 8|, and the latter then screwed down to scat on shoulder 84, thepiston and packer assembly rotating with the head as the latter is beingthreaded into the body.

The operation of the last described form of the invention is similar tothe previously described form, as will be apparent without the necessityfor repetitious description. It may be observed in passing, that themain difference in operation is the eifect of the tapered bore 8l) incausing radial contraction of the packer by inwardly displacing it asthe piston moves upwardly. Also it may be observed that this form ofhead is capable of operation as a stripper in the manner previouslydescribed, since the piston and packer are reciprocally displaceable, i.e., each is displaced in response to movement of the other.

The second variational form of the invention shown in Fig. 4 diiers fromthat ofv Fig. 3 in that it is designedy to provide a somewhat simplerand less expensive head intended, though not necessarily limited, foruse only as a blowout preventer. Here the piston stop screws areeliminated to simplify the construction and cheapen the cost ofmanufacture. This is permissible where the apparatus is to be used as ablow-out preventer (and the same applies to the previously described.

forms) since, although the provision of stop means for` limiting thefull conti-active position of the piston may be desirable, such meansmay be dispensed with inv favor of cheaper construction adapted to thespecific purpose. It will be noted that in Fig. 4, the samey type ofconnection at 68 is employed for attaching the body to the casing, areadily disconnectible joint of this type being desirable in order toenable the stripper head to be quickly applied to and removed from thecasing. Fig. 4 illustrates an additional feature in the provision of anannular shoulder 85 at the upper end oi the tapered bore 30, and whichis engaged` by the upper end of the packer so that the latter isconfined between shoulder 85 and the pistou shoulder, and held againstbodily upward movement as in the case of Fig. 3. As will be apparent,when the piston moves upward, the packer is radially constricted bylongitudinal compression as in the form or" Fig. l, and is alsosubjected to inward displacement as the rubber is pressed against thetapered surface 80.

To further simplify the construction in this form, the pressure fluidconnection with chamber i8 above the piston may be omitted, and merely avent opening provided. at 88 or some other suitable location. In theabsence of a pressure fluid connection for moving the piston downward.to open the packer, the latter may be'released from the work and thecontractor returned to its lower position, by relieving the wellpressure acting upwardly against the piston and packer. Thus, assuming ablow-outv to have occurred and the packer to have been closed by fluidpressure communicated through line to lspace 33, circulating mud may bepumped into thewell through cof the drill string to kill the' well,whereupon the pressure in space 33 may be released, permitting thepacker to expand longitudinally and move the piston down.

Figs. 5 and 6 show additional variant forms of the invention similar inprinciple to the described embodiments, but differing primarily in thearrangement of thepiston so that it moves downwardly in constricting thepacker, in opposition to the direction of pressure communication fromthe well, instead of moving upwardly with the well pressure, as in therst described forms. InFig. 5, the packer 88 is contained within theinverted cup-shaped piston 89 that slidably engages the bore 90 of bodysection 9|, the packer being attached to the shouldered wall y89a by thepreviously described type of connection generally indicated at 92. Theupper reduced diameter tubular portion 89h of the piston Vslidably tsbore 93 in the top wall of the body. The packer 88 is confined betweenthe piston shoulder 89a. andthe stationary upper end 94a of the lowerbody section 94, so that as the piston is moved downwardly by pressureuid communicated to chamber 95, the rubber is longitudinally compressedand radiallycontracted between the shoulders 89a and 94a. If desired, apressure iluid connection 96 may be provided for delivering operatingfluid to chamber 9'| to raise the contractor and release the packer. Thehead is shown to be mounted on the casing by threading the lower bodysection 94 on the upper end of the casing.

In Fig. 6, the inverted piston 98 is extended upwardly through bore 99in the top of the body |00, the top of the piston being exposed, withthe packer |0| attached to its under surface at |02. Upon downwardmovement of the piston, the packer is pressed against the downwardlytapering stationary surface |03 of the lower body section |04, thepiston being forced downwardly by uid pressure communicated to chamber|09. As in Fig. 5, the piston may be raised to release the packer bypressure iiuid introduced to chamber |06, or, in case the fluidconnection |06a is not used, by relieving the well pressure in themanner previously explained and allowing the packer to expand to releaseitself from sealing engagement with the work.

We claim:

1. In a packing head applied to a well pipe, a tubular housing adaptedto pass collared tubing through its bore, a packer in the housing andradially contractible about said tubing to prevent fluid escape fromsaid pipe through the housing, a continuously annular packer contractermovable vertically within the housing and directly engaging the packer,one end of said packer being bodily and vertically movable with saidco-ntractor in its contracting movement, a packer support, ilexiblemeans embedded in the packer and attached to said support, and means forselectively introducing into fluid-tight spaces Within said housing andsubstantially closed from communication with said well pipe through thehousing bore, uid under pressure to move the contracter'in oppositedirections and thereby to cause the packer to radially expand andcontract.

2. In a packing head applied to a well pipe, a tubular housing adaptedto pass collared tubing through its bore, a continuously annular packervthrough the housing, said packer having a longitudinally taperedportion, a continuously annular packer contracter movable verticallywithin the housing and directly engaging the packer, one end of saidpacker being bodily movable with said contracter in'its contractingmovement, a packer support, exible means embedded in the packer andattached to saidV support, Wedge means engaging said tapered portion ofthe packer and acting to radially constrict the packer during packercontracting movement of said contracter, and means for selectivelyintroducing into fluidtight spaces within said housing and substantiallyclosed from communication with said well pipe through the housing bore,fluid under pressure to actuate the contractor and thereby to cause thepacker-to radially expand and contract.

3. In a packing head applied to a well pipe, a tubular housing adaptedto pass collared pipe through its bore, a packer in the housing andradially contractible about said tubing to prevent iiuid escape fromsaid pipe through the housing, a continuously annular packer contractermovable vertically within theY housing and directly engaging andsurrounding theY outside of the packer, one end of said packer beingbodily movable with said contractor in its ,contracting movement,flexible means connecting said end of the packerv to the contracter, andmeans for introducing into a fluid-tight space within said housing andsubstantially closed from communication with said Well pipe through thehousing bore, fluid under pressure to actuate the contracter.

4. In a packing head applied to a well pipe, a tubular housing adaptedto pass collared tubing through its bore, a packer in the housing andradially contractible about said tubing to prevent fluid escape fromsaid pipe through the housing, I

a continuously annular packer contracter movable vertically withinV thehousing and directly engaging the packer, an annular. shoulder on saidcontracter supporting one end of said packer, said end of the packerbeing bodily Ymovable with the contracter in its contracting movement,supporting means stationary with relation tol the housing and supportingthe opposite end of the packer, fabric embedded in the packer andprojecting from the last mentioned end thereof, means connecting thefabric to said support, and means for selectively introducing intofluid-tight spaces within said housing and substantially closed fromcommunication with said well pipe through the housing bore, fluid underpressure to move the contracter in opposite directions and therebyr tocause the packer to radially expand and contract.

5. In a well pipe packing head, a tubular housing adapted totake anelongated member through its bore, a radially contractibleV packer inthe Vhousing and about said member, a'packer contracting piston movablevertically within the housing, one end ofsaid packer being suported.directly by and movable vertically with said piston in its contractingmovement, fabric embedded in said end of the packer and connected to thepiston, and a clamp ring securing said fabric to the piston.

6. In a well pipe packing head, a tubular housing adapted to take anelongatedv member through its bore, a radially contractible packer inthe housingV and about said member, a packer contracting piston movablevertically within the housing, one end of said packer being supporteddirectly by and movable vertically with said piston in its'contractingmovement, and fabric em.- bedded in said end of the packer and connectedto the piston. .f

7. In a packing head applied to a well pipe, a tubular housing adaptedto pass collared tubing through its bore, a packer contracting pistonmovable vertically Within the housing and having differential pressureareas, an annular shoulder formed on and within said piston, astationary annular shoulder spaced axially of the housing from saidpiston shoulder, a packer between said shoulders and surrounding thehousing bore, flexible means embedded Within and extending beyond theend of the packer, means attaching said ilexible means to saidstationary shoulder, the end of the packer adjacent the rst inentionedshoulder being bodily movable with the piston, valve means forselectively introducing into fluid-tight spaces Within said housing andsubstantially closed from communication with said well pipe through thehousing bore, fluid under pressure acting against said differentialpiston areas to move the piston in opposite directions.

8. In a packing head applied to a Well pipe, a tubular housing adaptedto pass oollared pipe through its bore, a packer contracting pistonmovable vertically within the housing, an annular shoulder formed on andWithin said piston, a sta tionary shoulder spaced axially of the housingfrom said piston shoulder, a packer between said shoulders andsurrounding the housing bore, fabric embedded Within the packer, meansattaching said fabric to said stationary shoulder, means forming on saidcontracter oppositely facing differential area pressure surfacesintermediate its ends, and means for selectively introducing into'fluid-tight spaces Within said housing and substantially closed fromcommunication with said well pipe through the housing bore, fluid underpressure acting against said dilerential area surfaces to move thecontracter in opposite directions and thereby to cause the packer toYradially expand and contract, the end of the packer nearest said annularshoulder being bodily movable with the piston.

ALBERT L. STONE. FRANK R. SEAVER.

